1. Field of the Invention
The present invention relates to a breather apparatus of an internal combustion engine, which separates and collects an oil content in blowby gas.
2. Description of the Related Art
A blowby gas passing through sliding portions of a piston and cylinder and leaking from an engine main body includes an oil content. Therefore, a breather apparatus is attached to an engine (internal combustion engine). Accordingly, the oil content in the blowby gas is separated, and oil is returned into inner components of the engine such as an oil pan.
Usually in a recipro engine, the breather apparatus for separating the oil content from the blowby gas is disposed in an inner surface of a cam cover attached to an upper part of a cylinder head. Since the breather apparatus is built in the cam cover in this structure, an overall height of the engine main body increases.
In the engine whose overall height is required to be lowered, the breather apparatus is installed outside the engine main body. However, when the breather apparatus is installed outside the engine main body, a place for mounting the breather apparatus has to be secured in a limited small engine room. Additionally, a hose needs to be used to connect the engine main body to the breather apparatus, and it is necessary to circulate the blowby gas or the collected oil in the hose. Therefore, it is necessary to secure a place for disposing the hose in the engine room. Additionally, there is a problem that a structure around the engine main body becomes complicated.
Therefore, for example, as in the breather apparatus disclosed in Jpn. Pat. KOKOKU Publication No. 7-99088, it has been proposed that an oil separation chamber be formed in the inner surface of a chain cover attached to the engine.
The breather apparatus is requested to enhance a capability to separate the oil. Therefore, the separation chamber having a large capacity is required. However, only a limited space can be secured inside the chain cover because of various disposed apparatuses, and it is difficult to secure a large-sized separation chamber inside a chain case.